Record for talking-machines.



A. N. PETIT, DECD.

. TTTTTTTTTTTTTTTTTTT R.

RECORD FOR TALKING FILED MACHINES.

Patented Nov. 13, 1917,

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UNITED STATES mm onmon.

ADEMOR N. PETIT, OF ORANGE, NEW JERSEY; ALBERT 0. PETIT, ADMINISTRATOR 0F SAID ADEMOR N. PETIT, DECEASED, ASSIGNOR TO JOHN L. LOTSCH, TRUSTEE, OF

BROOKLYN, NEW YORK.

RECORD FOR TALKING-MACHIN ES.

Specification of Letters Patent.

Patented Nov. 13, 1917.

Application filed February 12, 1914, Serial No. 818,349. Renewed April 14, 1917. Serial No. 162,144.

To all whom it may concern:

Be it known that I, ADEMOR N; Pn'rrr, a citizen of the United 7 States, residing at Orange, county of Essex, and State of New Jersey, have invented a certain new and useful Record for Talking-Machines, of which the following is a speclfication.

Myinvention relates to records of the type wherein a sinuous groove of substantially uniform depth, is cut into a tablet which is caused to rotate beneath a cutting tool of the proper shape and configuration, and its object is to produce an improved record groove, the walls of which are so proportioned and shaped as to reproduce the sounds which were employed to produce the original record, with more clearness and distinctness than has been possible from records heretofore devised.

Another object is to produce a record groove which will retain its shape and reproduce the recorded sounds .with fidelity and without false tones.

A further objectis to produce a record groove wherein the reproducing tool will always properly engage therecord surface notwithstanding the wear to which the tool may be subjected.

These and further objects will more fully appear in the following specification and accompanying drawings taken together or separately. a

Numerous patents have been granted on records having grooves of various configurations. The earliest form was that traced on a smooth surface covered with carbon dust. This dust was displaced and left a shallow groove in the carbon. The next step was the. production of a groove by indenting in a metal foil or in wax or by the concurrently devised method of tracing through a wax film deposited upon metal and then etching; then followed a cutting tool which formed a groove with sloping walls and a fiat bottom similar to a standard screw thread. Then followed a shallow round bottomed groove cut in relatively hard material- This was followed by grooves of semi-elliptical shape and of considerable depth. Then came the V shaped groove. These forms are mentioned as commercially developed but in fact the early experimenters tested many thereof concurrently, being limited only by their several choices of material. Various other forms of record grooves have been suggestedbut all of them are along the same general lines as those noted above.

In all of the record grooves with which I am familiar the Walls of the groove terminate at the plane of the record surface in sharp angles and form sharp and consequently thin fragile edges. are, because of the nature of the material of which records are composed, more or less ragged or what is known in cutting tools as wireedged, and the rough edges produce false vibrations even upon the first use of the record. The fact that the edges of the grooves are ragged causes them to crumble and disintegrate by reason of the friction of the reproducing stylus against them and in a comparatively short time the edges are broken down and the effect of the false vibrations induced by them is greatly increased. The rough edges of the groove also act. as grinding surfaces against which the stylus is held and consequently it is soon worn to such an extent that shoulders are formed, which shoulders rest upon the surface of the disk and further tend to produce discordant sounds. This grinding ac-- tion on the stylus or needle is so rapid that in most cases, before the needle reaches the end'of the record groove on its first reproduction the same is clearly noticeable and the nearer to the end of the groove the needle approaches the greater the wear on the needle and the record and the more apparent becomes the distortion of the sound reproduction.

By means of my improved record the objectionable features above described will be completely eliminated and this advantage is obtained by so fashioning and forming the record groove that the side walls'will not join the plane of the record surface at angles, but will merge into that surface by easy curves thereby eliminating the sharp angles with their consequent weakened and friable edges. The cutting tool for forming my improved record groove is not claimed herein, but is made the subject matter of a separate application filed on even date herewit In the drawings- Figure 1 is a sectional view of a portion of a talking machine showing a recording tool in operative relation thereto.

The sharp thin edges Fig. 2 is a sectional view of the same, taken at right angles to Fig. 1.

Fig. 3 is an enlarged sectional view of a record groove and cutting tool.

Fig. 4 is a similar View of the groove showing a reproducing stylus of ordinary construction engaging with the groove.

Figs. 5, 6, 7 and 8 are sectlonal views of modified forms of groove.

Fig. 9 is an enlarged plan view of a portion of the record groove.

' the turntable and the recorder is adjudged in proper position, the cutter will engage the blank and, when the same is rotated against the cutting edge and slowly moved diametrically under the cutting tool, a spiral groove of the required, uniform depth will be cut in the blank. If now the diaphragm be vibrated, by atmospheric compressions or sound waves impinging thereon, the recordin tool will be moved from side to side and t e groove or record instead of being a true spiral will be a sinuous groove extending spirally over the surface of the blank.

The preferred form of my improved record groove 14 is shown particularly in Figs. 3 and 4. The groove is trough shape with a rounded bottom 15, and diverging walls 16. The upper parts of the walls are curved as at 17 and these curves merge into the fiat surface 18 of the disk 10. The record so made is used as a master for the production of a matrix and from this any number of hard reproducing records.

WVhen reproducing, the stylus in traversing the record groove will bear against both sides thereof in being fed across the surface of the disk and will bear against a rounded and relatively long surface instead of bearing against a thin sharp ed e as heretofore, and the rounded portions eing part of the record of the sound vibrations, the'reproductions will be true, due to the rounded edges of the groove, and both record and stylus will wear and remain serviceable much longer.

It is obvious that vvarious modifications may be made without departing from the object of my invention.

It is to be understood that I do not limit myself to a disk record and it is obvious that the invention herein described and disclosed is equally applicable to the cylindrical and other types of record.

In accordance with the provisions of the patent statute, I have now described my invention together with the apparatus which I consider to represent the best embodiment thereof, but I desire it to be understood that the apparatus is merely illustrative and that my invention is not to be so limited, but may be carried out in other ways.

Having now described my invention, what I claim and desire to secure by Letters Patent is:

1. A sound record having a laterally undulatory cut groove of substantially uniform depth, the Walls of said groove merging into the surface of the record.

2. A sound record having a laterally undulatory cut groove of substantially uniform depth, and curved surfaces joining the walls of the groove to the surface of the record.

3. A sound record having a laterally undulatory cut groove of substantially uniform depth, the walls of said groove diverging from the bottom thereof and merging into the surface of the record.

4. A sound record having a laterally undulatory cut groove of substantially uniform depth, the walls of the groove diverging from the bottom thereof and joining the surface of the record by easy curves.

This specification signed and witnessed this 11th day of February, 1914.

ADEMOR N. PETIT.

Witnesses:

JOHN L. Lorsorr, ELIJAH F. MUNN, Jr. 

